1. Field of the Invention
The present invention relates to a noise dampener for a motor vehicle door lock including a door arrester bar which pivots about an axis extending parallel to a motor vehicle door hinge axis, which is pivotally secured to one of the door assembly parts, a door or a door pillar, with a bearing bolt extending through a bearing bore formed in an end region of the door arrester bar and supported in a bearing block, and which extends into a retaining housing secured to another of the door assembly parts and having locking means cooperating with detent marks provided in the door arrester bar for retaining same, with the noise dampener being formed of a non-metallic, noise dampening material, surrounding, at least partially, the pivotally securable end region of the door arrester bar, and provided with means for preventing longitudinal displacement of the noise dampener relative to the end region of the door arrester bar.
2. Description of the Prior Art
The door locks of the type described above are locked, during opening or closing of the door, with the door arrester bar which extends into the retaining housing and is secured there with the spring-biased locking means which cooperates with the detent marks provided on the door arrester bar. Thereby, the door can be held in one or more opening positions. Because the door lock parts are mass-produced parts, the discrepancy between the manufacturing tolerances of the bearing bolt for securing the door arrester bar and the bearing bore in which the bearing bolt is received, are inevitable. Because of the possible discrepancy of tolerances, the bearing bolt can extend through the bearing bore either with a relatively large clearance or with a press fit.
When a tolerance discrepancy results in a press fit, it causes difficulties, at least initially, in the attachment of the door arrester bar to the door assembly part. A tolerance discrepancy which results in a clearance fit, leads to that the door arrester bar, which is longitudinally displacable due to cooperation of the locking bodies with the detent marks provided on the door arrester bar, impacts on the bearing bolt causing generation of an unpleasant, undesirable, audible noise.
In order to reduce a possible tolerance discrepancy between the bearing bolt and the bolt-receiving bearing bore, which is formed in the end region of the door arrester bar, and thereby to eliminate or substantially reduce the audible noise resulting from the tolerance discrepancy, German publication DE-OS 40 06 572 suggests to provide a split taper socket, which is formed as a spring sleeve, between the inner wall of the bearing bore and the bearing bolt. Thereby the bearing bolt becomes fixedly secured in the bearing bore, without the possibility of the door arrester bar moving relative thereto. Such a socket permits to eliminate the tolerance discrepancy to a most possible extent, thus eliminating the undesired audible noise. However, the attachment the door arrester bar with the use of a spring socket results in increase of the manufacturing costs. Further, using the split socket results in increase of the assembly time and necessitate use of particular tools.
German Publication DE-OS 37 22 996 suggests for reducing the tolerance discrepancy between the bearing bolt and the bearing bore, to provide a spring element between the bearing block and the door arrester bar, which is formed as a U-shaped snap-on clip pushed onto the end of the door arrester bar and the legs of which have recesses between which the bearing bolt is received. The U-shaped snap-on clip should act as a brake which would prevent the relative movement between the door arrester bar and the bearing bolt in case of an increased clearance, eliminating, theoretically, any audible noise. Because such a snap-on clip should apply an adequate spring force to prevent a relative movement between the door arrester bar and the bearing bolt, it complicates the attachment of the door arrester bar. Further, because such a snap-on clip is made of metal, it cannot dampen or reduce noise which still can be generated by the relative movement between the door arrester bar and the bearing block.
It was further proposed to provide, in the region of the bearing bolt, a fold element formed of a non-metallic material instead of the U-shaped clip, with the fold element having spaced surface portions, which are connected by a connection web, overlap the wide sides of the door arrested bar, and have a through-bore through which the bearing bolt extends. Both free edges of the surface portions are provided with clipping tabs for retaining the free end of the door arrester bar. However, the use of the fold element, which is formed on a non-metallic, in particular, plastic material, does not permit, because of a certain underpressure and a slow braking action, to completely eliminate the relative movement between the door arrester bar and the bearing bolt, in particular when the clearance is relatively large, and thus, to eliminate a possible audible noise. A particular drawback associated with the use of the fold element consists in that it is relatively difficult to mount the fold element onto the end of the door arrester bar and in that the clip tabs, which are provided on the free edges of the surface portions, which overlap the door arrester bar, do not adequately prevent disengagement of the fold element from the door arrester bar.
Accordingly, an object of the present invention is to provide a noise dampener which would reliably prevent any audible noise resulting from displacement of the door arrester bar relative to the bearing bolt.
Another object of the present invention is to provide a noise dampener having a simple construction and which can be easily mounted on the door arrester bar.